Tom, the air is forced up through the leak-off pipes and back to the tank, thereby purging the system of air sufficiently that the engine will fire. Putting your foot on the accelerator will have absolutely no effect before the engine starts, thanks to the ecu. Easy start/brake cleaner/anything similar might be worth a try, but i've not had much luck with it myself at times when there's obviously another issue. CR diesels can be a shit to purge though, i try to avoid taking fuel components out unless i'm sure it's necessary.
Chris, the copper washers won't be leaking diesel, it'll be combustion waste or nothing coming from there, it's fairly likely that's a separate issue. The diesel must be coming from somewhere on the injection system, have you tried tightening the unions a little as suggested by Gareth? Another prime candidate is your leak-off o-rings. Is there diesel down the side of the injectors at all?
Chris, the copper washers won't be leaking diesel, it'll be combustion waste or nothing coming from there, it's fairly likely that's a separate issue. The diesel must be coming from somewhere on the injection system, have you tried tightening the unions a little as suggested by Gareth? Another prime candidate is your leak-off o-rings. Is there diesel down the side of the injectors at all?